Forwarding and Control Element Separation (forces)
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Charter
Last Modified: 2007-09-26
Current Status: Active Working Group
Chair(s):
David Putzolu
Patrick Droz
Routing Area Director(s):
Ross Callon
David Ward
Routing Area Advisor:
David Ward
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Description of Working Group:
The emergence of off-the-shelf network processor devices that
implement
the fast path or forwarding plane in network devices such as routers,
along with the appearance of a new generation of third party
signaling,
routing, and other router control plane software, has created the need
for standard mechanisms to allow these components to be combined into
functional wholes. ForCES aims to define a framework and associated
mechanisms for standardizing the exchange of information between the
logically separate functionality of the control plane, including
entities such as routing protocols, admission control, and signaling,
and the forwarding plane, where per-packet activities such as packet
forwarding, queuing, and header editing occur. By defining a set
of standard mechanisms for control and forwarding separation, ForCES
will enable rapid innovation in both the control and forwarding
planes.
A standard separation mechanism allows the control and forwarding
planes to innovate in parallel while maintaining interoperability.
The products of this working group will be:
o A set of requirements for mechanisms to logically
separate the control and data forwarding planes of
an IP network element (NE)
o An applicability statement for the ForCES model
and protocol
o Informational RFCs as necessary documenting current
approaches to the functional model and controlled
objects therein
o An architectural framework defining the entities
comprising a ForCES network element and identifying
the interactions between them.
o A description of the functional model of a
Forwarding Element
o A formal definition of the controlled objects in the
functional model of a forwarding element. This
includes IP forwarding, IntServ and DiffServ QoS. An
existing specification language shall be used for
this task.
o Specification of IP-based protocol for transport of the
controlled objects. When the control and forwarding devices
are separated beyond a single hop, ForCES will make use of an
existing RFC2914 compliant L4 protocol with adequate reliability,
security and congestion control (e.g. TCP, SCTP) for transport
purposes.
The main focus area of the working group will be control and
forwarding separation for IP forwarding devices where the
control and forwarding elements are in close (same room/small
number of hops) or very close (same box/one hop) proximity. Other
scenarios will be considered but at not the main focus of the
work. The functional model of the forwarding element will include
QoS (DiffServ and IntServ) capabilities of modern networking
devices such as routers. In order to minimize the effort to
integrate forwarding elements and control elements, a mechanism
for auto discovery and capability information exchange will form
an integral part of the standardized interface.
ForCES will coordinate with other standards bodies and working
groups as appropriate. Examples of such bodies include IETF/GSMP,
IETF/Megaco, the Network Processing Forum (NPF), the Multiservice
Switching Forum (MSF), IEEE P1520, and SoftSwitch. ForCES will
review relevant protocol efforts such as GSMP and Megaco and will
extend or reuse them if appropriate. If protocol reuse is
accepted as satisfactory for fulfilling the ForCES requirements
then ForCES may recharter to adopt specific deliverables around
the selected protocol.
Goals and Milestones:
Done Submit requirements document to IESG
Done Submit framework document to IESG
Nov 2004 Submit forwarding element functional model document to IESG
Mar 2005 Submit formal definition of controlled objects in functional
model
Mar 2005 Submit protocol selection/definition document to IESG
Mar 2005 Submit applicability statement to IESG
Internet-Drafts:
Posted Revised I-D Title
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Aug 2003 Oct 2007
ForCES Forwarding Element Model
Sep 2004 Nov 2007
ForCES Protocol Specification
Jan 2006 Mar 2007
ForCES MIB
Nov 2007 Nov 2007
SCTP based TML (Transport Mapping Layer) for ForCES protocol
Request For Comments:
RFC Stat Published Title
------- -- ----------- ------------------------------------
RFC3549 I Jul 2003 Linux Netlink as an IP Services Protocol
RFC3654 I Dec 2003 Requirements for Separation of IP Control and Forwarding
RFC3746 I Apr 2004 Forwarding and Control Element Separation (ForCES)
Framework